1. Field of the Invention
The present invention relates to an elastic wave device such as an elastic wave resonator or an elastic wave filter, and to a manufacturing method therefor.
2. Description of the Related Art
Heretofore, various elastic wave devices have been used as resonators and band pass filters. Japanese Unexamined Patent Application Publication No. 2007-251910 discloses an elastic wave device in which Lamb waves are utilized as plate waves. In Japanese Unexamined Patent Application Publication No. 2007-251910, an IDT electrode is formed on a piezoelectric substrate. A reinforcement substrate having an opening therein that opens upward is bonded to a lower surface of the piezoelectric substrate. The opening is provided below a part of the piezoelectric substrate where the IDT electrode is provided. The opening is closed by the piezoelectric substrate and a hollow part is thus formed.
In elastic wave devices, in addition to an IDT electrode, a plurality of wiring lines are provided that are connected to the IDT electrode. Although there is no particular mention of such wiring lines in Japanese Unexamined Patent Application Publication No. 2007-251910, it is sometimes not possible to obtain good characteristics due to parasitic capacitances between wiring lines and so forth when an elastic wave device is actually manufactured.